Category: Default

VMS has been around for almost 30 years, but there’s still a lot of confusion about its name. Insiders call it “VMS”, but the official product name has changed over time.

VAX-11/VMS was the original name of the operating system. The “-11” was in there to link it to the PDP-11, which was DEC’s flagship computer until replaced by VAX. Early VAX systems could even run PDP-11 code.

The name changed to VAX/VMS at around V2.0. By that point, the PDP-11 was sufficiently ancient to ignore — although PDP-11’s were sold for many years afterwards.

When the VMS operating system was ported to the Alpha platform, VMS-AXP was used. The codebase for VMS was forked to create the Alpha version around V5.0.

VMS was was renamed OpenVMS to signify the high degree of support for industry standards. This happened around V6.0, at which time the two platforms were feature-identical again. The code bases were not merged, however.

Hewlett-Packard has begun to refer to VMS as “OVMS“. My guess is that they’re trying to reduce confusion with OpenView, a datacenter management product also sold by HP. If you call their support center and say “OpenVMS” instead of “OVMS”, you’ll get routed to the wrong place — even they’re confused!